lancet/docs/slice.md

# Slice
Package slice implements some functions to manipulate slice.

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## Source:

[https://github.com/duke-git/lancet/blob/v1/slice/slice.go](https://github.com/duke-git/lancet/blob/v1/slice/slice.go)


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## Usage:
```go
import (
    "github.com/duke-git/lancet/slice"
)
```

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## Index
- [Contain](#Contain)
- [ContainSubSlice](#ContainSubSlice)
- [Chunk](#Chunk)
- [Compact](#Compact)
- [Concat](#Concat)
- [Count](#Count)
- [Difference](#Difference)
- [DifferenceBy](#DifferenceBy)
- [DeleteByIndex](#DeleteByIndex)
- [Drop](#Drop)
- [Every](#Every)
- [Filter](#Filter)
- [Find](#Find)
- [FindLast](#FindLast)
- [FlattenDeep](#FlattenDeep)
- [ForEach](#ForEach)
  
- [GroupBy](#GroupBy)
- [IntSlice](#IntSlice)
- [InterfaceSlice](#InterfaceSlice)
- [Intersection](#Intersection)
- [InsertByIndex](#InsertByIndex)
- [Map](#Map)
- [ReverseSlice](#ReverseSlice)
- [Reduce](#Reduce)
- [Shuffle](#Shuffle)
- [SortByField](#SortByField)
- [Some](#Some)
- [StringSlice](#StringSlice)
- [Unique](#Unique)
- [Union](#Union)
- [UpdateByIndex](#UpdateByIndex)
- [Without](#Without)

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## Documentation

## Note:
1. param which type is interface{} in below functions should be slice.

### <span id="Contain">Contain</span>
<p>Check if the value is in the slice or not. iterableType param can be string, map or slice.</p>

<b>Signature:</b>

```go
func Contain(iterableType interface{}, value interface{}) bool
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	res := slice.Contain([]string{"a", "b", "c"}, "a")
	fmt.Println(res) //true
}
```


### <span id="ContainSubSlice">ContainSubSlice</span>
<p>Check if the slice contain subslice or not.</p>

<b>Signature:</b>

```go
func ContainSubSlice(slice interface{}, subslice interface{}) bool
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	res := slice.ContainSubSlice([]string{"a", "b", "c"}, []string{"a", "b"})
	fmt.Println(res) //true
}
```




### <span id="Chunk">Chunk</span>
<p>Creates an slice of elements split into groups the length of `size`.</p>

<b>Signature:</b>

```go
func Chunk(slice []interface{}, size int) [][]interface{}
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	arr := []string{"a", "b", "c", "d", "e"}
	res := slice.Chunk(InterfaceSlice(arr), 3)
	fmt.Println(res) //[][]interface{}{{"a", "b", "c"}, {"d", "e"}}
}
```



### <span id="Compact">Compact</span>
<p>Creates an slice with all falsey values removed. The values false, nil, 0, and "" are falsey.</p>

<b>Signature:</b>

```go
func Compact(slice interface{}) interface{}
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	res := slice.Compact([]int{0, 1, 2, 3})
	fmt.Println(res) //[]int{1, 2, 3}
}
```


### <span id="Concat">Concat</span>
<p>Creates a new slice concatenating slice with any additional slices and/or values.</p>

<b>Signature:</b>

```go
func Concat(slice interface{}, values ...interface{}) interface{}
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	res1 := slice.Concat([]int{1, 2, 3}, 4, 5)
	fmt.Println(res1) //[]int{1, 2, 3, 4, 5}

	res2 := slice.Concat([]int{1, 2, 3}, []int{4, 5})
	fmt.Println(res2) //[]int{1, 2, 3, 4, 5}
}
```



### <span id="Count">Count</span>
<p>Count iterates over elements of slice, returns a count of all matched elements. The function signature should be func(index int, value interface{}) bool.</p>

<b>Signature:</b>

```go
func Count(slice, function interface{}) int
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	nums := []int{1, 2, 3, 4, 5, 6}
	evenFunc := func(i, num int) bool {
		return (num % 2) == 0
	}

	res := slice.Count(nums, evenFunc)
	fmt.Println(res) //3
}
```




### <span id="Difference">Difference</span>
<p>Creates an slice of whose element not included in the other given slice.</p>

<b>Signature:</b>

```go
func Difference(slice1, slice2 interface{}) interface{}
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	s1 := []int{1, 2, 3, 4, 5}
	s2 := []int{4, 5, 6}

	res := slice.Difference(s1, s2)
	fmt.Println(res) //[]int{1, 2, 3}
}
```




### <span id="DifferenceBy">DifferenceBy</span>
<p>DifferenceBy accepts iteratee func which is invoked for each element of slice and values to generate the criterion by which they're compared.</p>

<b>Signature:</b>

```go
func DifferenceBy(slice interface{}, comparedSlice interface{}, iterateeFn interface{}) interface{}
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	s1 := []int{1, 2, 3, 4, 5}
	s2 := []int{4, 5, 6}
	addOne := func(i int, v int) int {
		return v + 1
	}

	res := slice.DifferenceBy(s1, s2, addOne)
	fmt.Println(res) //[]int{1, 2}
}
```




### <span id="DeleteByIndex">DeleteByIndex</span>
<p>Delete the element of slice from start index to end index - 1.</p>

<b>Signature:</b>

```go
func DeleteByIndex(slice interface{}, start int, end ...int) (interface{}, error)
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	res1 := slice.DeleteByIndex([]string{"a", "b", "c", "d", "e"}, 3)
	fmt.Println(res1) //[]string{"a", "b", "c", "e"}

	res2 := slice.DeleteByIndex([]string{"a", "b", "c", "d", "e"}, 0, 2)
	fmt.Println(res2) //[]string{"c", "d", "e"}

}
```




### <span id="Drop">Drop</span>
<p>Creates a slice with `n` elements dropped from the beginning when n > 0, or `n` elements dropped from the ending when n < 0.</p>

<b>Signature:</b>

```go
func Drop(slice interface{}, n int) interface{}
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	res1 := slice.Drop([]int{}, 0)
	fmt.Println(res1) //[]int{}

	res2 := slice.Drop([]int{1, 2, 3, 4, 5}, 1)
	fmt.Println(res2) //[]int{2, 3, 4, 5}

	res3 := slice.Drop([]int{1, 2, 3, 4, 5}, -1)
	fmt.Println(res3) //[]int{1, 2, 3, 4}
}
```




### <span id="Every">Every</span>
<p>Return true if all of the values in the slice pass the predicate function. The function signature should be func(index int, value interface{}) bool.</p>

<b>Signature:</b>

```go
func Every(slice, function interface{}) bool
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	nums := []int{1, 2, 3, 5}
	isEven := func(i, num int) bool {
		return num%2 == 0
	}

	res := slice.Every(nums, isEven)
	fmt.Println(res) //false
}
```




### <span id="Filter">Filter</span>
<p>Return all elements which match the function. Function signature should be func(index int, value interface{}) bool.</p>

<b>Signature:</b>

```go
func Filter(slice, function interface{}) interface{}
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	nums := []int{1, 2, 3, 5}
	isEven := func(i, num int) bool {
		return num%2 == 0
	}

	res := slice.Filter(nums, isEven)
	fmt.Println(res) //[]int{2, 4}
}
```



### <span id="Find">Find</span>
<p>Iterates over elements of slice, returning the first one that passes a truth test on function.function signature should be func(index int, value interface{}) bool.</p>

<b>Signature:</b>

```go
func Find(slice, function interface{}) (interface{}, bool)
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	nums := []int{1, 2, 3, 5}
	isEven := func(i, num int) bool {
		return num%2 == 0
	}

	res, ok := slice.Find(nums, even)
	fmt.Println(res) //2
	fmt.Println(ok) //true
}
```




### <span id="FindLast">FindLast</span>
<p>iterates over elements of slice from end to begin, returning the last one that passes a truth test on function. The function signature should be func(index int, value interface{}) bool.</p>

<b>Signature:</b>

```go
func FindLast(slice, function interface{}) (interface{}, bool)
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	nums := []int{1, 2, 3, 5}
	isEven := func(i, num int) bool {
		return num%2 == 0
	}

	res, ok := slice.FindLast(nums, even)
	fmt.Println(res) //4
	fmt.Println(ok) //true
}
```



### <span id="FlattenDeep">FlattenDeep</span>
<p>flattens slice recursive.</p>

<b>Signature:</b>

```go
func FlattenDeep(slice interface{}) interface{}
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	arr := [][][]string{{{"a", "b"}}, {{"c", "d"}}}
	res := slice.FlattenDeep(arr)
	fmt.Println(res) //[]string{"a", "b", "c", "d"}
}
```





### <span id="ForEach">ForEach</span>
<p>Iterates over elements of slice and invokes function for each element, function signature should be func(index int, value interface{}).</p>

<b>Signature:</b>

```go
func ForEach(slice, function interface{})
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	numbers := []int{1, 2, 3, 4, 5}
	var numbersAddTwo []int
	slice.ForEach(numbers, func(index int, value int) {
		numbersAddTwo = append(numbersAddTwo, value+2)
	})
	fmt.Println(numbersAddTwo) //[]int{3, 4, 5, 6, 7}
}
```




### <span id="GroupBy">GroupBy</span>
<p>Iterates over elements of the slice, each element will be group by criteria, returns two slices. The function signature should be func(index int, value interface{}) bool.</p>

<b>Signature:</b>

```go
func GroupBy(slice, function interface{}) (interface{}, interface{})
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	nums := []int{1, 2, 3, 4, 5, 6}
	evenFunc := func(i, num int) bool {
		return (num % 2) == 0
	}
	even, odd := slice.GroupBy(nums, evenFunc)

	fmt.Println(even) //[]int{2, 4, 6}
	fmt.Println(odd) //]int{1, 3, 5}
}
```




### <span id="IntSlice">IntSlice</span>
<p>Convert interface slice to int slice.</p>

<b>Signature:</b>

```go
func IntSlice(slice interface{}) []int
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	var nums = []interface{}{1, 2, 3}
	res := slice.IntSlice(nums)
	fmt.Println(res) //[]int{1, 2, 3}
}
```




### <span id="InterfaceSlice">InterfaceSlice</span>
<p>Convert value to interface slice.</p>

<b>Signature:</b>

```go
func InterfaceSlice(slice interface{}) []interface{}
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	var nums = []int{}{1, 2, 3}
	res := slice.InterfaceSlice(nums)
	fmt.Println(res) //[]interface{}{1, 2, 3}
}
```




### <span id="Intersection">Intersection</span>
<p>Creates a slice of unique values that included by all slices.</p>

<b>Signature:</b>

```go
func Intersection(slices ...interface{}) interface{}
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	s1 := []int{1, 2, 2, 3}
	s2 := []int{1, 2, 3, 4}
	res := slice.Intersection(s1, s2),

	fmt.Println(res) //[]int{1, 2, 3}
}
```




### <span id="InsertByIndex">InsertByIndex</span>
<p>insert the element into slice at index.</p>

<b>Signature:</b>

```go
func InsertByIndex(slice interface{}, index int, value interface{}) (interface{}, error)
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	s := []string{"a", "b", "c"}
	
	res1, _ := slice.InsertByIndex(s, 0, "1")
	fmt.Println(res1) //[]string{"1", "a", "b", "c"}

	res2, _ := slice.InsertByIndex(s, 3, []string{"1", "2", "3"})
	fmt.Println(res2) //[]string{"a", "b", "c", "1", "2", "3"}
}
```




### <span id="Map">Map</span>
<p>Creates an slice of values by running each element in slice thru function, function signature should be func(index int, value interface{}) interface{}.</p>

<b>Signature:</b>

```go
func Map(slice, function interface{}) interface{}
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	nums := []int{1, 2, 3, 4}
	multiplyTwo := func(i, num int) int {
		return num * 2
	}
	res := slice.Map(nums, multiplyTwo)
	fmt.Println(res) //[]int{2, 4, 6, 8}
}
```




### <span id="ReverseSlice">ReverseSlice</span>
<p>Reverse the elements order in slice.</p>

<b>Signature:</b>

```go
func ReverseSlice(slice interface{})
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	nums := []int{1, 2, 3, 4}
	slice.ReverseSlice(nums)
	fmt.Println(res) //[]int{4, 3, 2, 1}
}
```



### <span id="Reduce">Reduce</span>
<p>Reduce slice, function signature should be func(index int, value1, value2 interface{}) interface{}.</p>

<b>Signature:</b>

```go
func Reduce(slice, function, zero interface{}) interface{}
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	nums := []int{1, 2, 3, 4}
	reduceFunc := func(i, v1, v2 int) int {
		return v1 + v2
	}
	res := slice.Reduce(nums, reduceFunc, 0)
	fmt.Println(res) //10
}
```




### <span id="Shuffle">Shuffle</span>
<p>Creates an slice of shuffled values.</p>

<b>Signature:</b>

```go
func Shuffle(slice interface{}) interface{}
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	nums := []int{1, 2, 3, 4, 5}
	res := slice.Shuffle(nums)
	fmt.Println(res) //3,1,5,4,2
}
```



### <span id="SortByField">SortByField</span>
<p>Sort struct slice by field. Slice element should be struct, field type should be int, uint, string, or bool. Default sort type is ascending (asc), if descending order, set sortType to desc</p>

<b>Signature:</b>

```go
func SortByField(slice interface{}, field string, sortType ...string) error
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	type student struct {
		name string
		age  int
	}
	students := []student{
		{"a", 10},
		{"b", 15},
		{"c", 5},
		{"d", 6},
	}
	err := slice.SortByField(students, "age", "desc")
	if err != nil {
		fmt.Println(err)
	}
	fmt.Println(students) 
	// []students{
	// 	{"b", 15},
	// 	{"a", 10},
	// 	{"d", 6},
	// 	{"c", 5},
	// }
}
```



### <span id="Some">Some</span>
<p>Return true if any of the values in the list pass the predicate function, function signature should be func(index int, value interface{}) bool.</p>

<b>Signature:</b>

```go
func Some(slice, function interface{}) bool
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	nums := []int{1, 2, 3, 5}
	isEven := func(i, num int) bool {
		return num%2 == 0
	}

	res := slice.Some(nums, isEven)
	fmt.Println(res) //true
}
```



### <span id="StringSlice">StringSlice</span>
<p>Convert interface slice to string slice.</p>

<b>Signature:</b>

```go
func StringSlice(slice interface{}) []string
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	var s = []interface{}{"a", "b", "c"}
	res := slice.StringSlice(s)
	fmt.Println(res) //[]string{"a", "b", "c"}
}
```




### <span id="Unique">Unique</span>
<p>Remove duplicate elements in slice.</p>

<b>Signature:</b>

```go
func Unique(slice interface{}) interface{}
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	res := slice.Unique([]int{1, 2, 2, 3})
	fmt.Println(res) //[]int{1, 2, 3}
}
```



### <span id="Union">Unique</span>
<p>Creates a slice of unique values, in order, from all given slices. using == for equality comparisons.</p>

<b>Signature:</b>

```go
func Union(slices ...interface{}) interface{}
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	s1 := []int{1, 3, 4, 6}
	s2 := []int{1, 2, 5, 6}
	res := slice.Union(s1, s2)

	fmt.Println(res) //[]int{1, 3, 4, 6, 2, 5}
}
```



### <span id="UpdateByIndex">UpdateByIndex</span>
<p>Update the slice element at index. if param index < 0 or index >= len(slice), will return error. </p>

<b>Signature:</b>

```go
func UpdateByIndex(slice interface{}, index int, value interface{}) (interface{}, error)
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	s := []string{"a", "b", "c"}
	
	res1, _ := slice.UpdateByIndex(s, 0, "1")
	fmt.Println(res1) //[]string{"1", "b", "c"}
}
```




### <span id="Without">Without</span>
<p>Creates a slice excluding all given values. </p>

<b>Signature:</b>

```go
func Without(slice interface{}, values ...interface{}) interface{}
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/slice"
)

func main() {
	res := slice.Without([]int{1, 2, 3, 4, 5}, 1, 2)
	fmt.Println(res) //[]int{3, 4, 5}
}
```